The present invention relates to an emergency communication device which is mounted in a mobile body such as a vehicle, especially an automobile, and which transmits emergency data by radio waves as a mobile center to an emergency communication receiving center when an emergency such as an accident or theft has occurred. More particularly the present invention relates to an emergency communication device provided with a self-diagnosing function which performs self diagnosis by repeatedly transmitting and receiving (hereafter transceiving) test data under normal conditions.
A Conventional type of emergency communication device executes communication of emergency data to an emergency communication receiving center when a vehicle in which the device is mounted encounters an accident and the device is either automatically detects the accident or is activated by the driver pushing an emergency communication button, or when a communication antenna is broken due to the vehicle being stolen. Although such emergency communication devices are not widely used, there is no point if the device fails during use in such an emergency as above. Furthermore if the antenna is broken, communication can not be performed.
A conventional example of an emergency communication device provided with a self diagnosing function is provided by JP-A-4-123954. The device provide a plurality of antennas in a vehicle. The respective antennas are continuously switched between transmitters and receivers in fixed time intervals. Transmission from the switched antennas with an emergency communication receiving center by test data is repeatedly carried out through a circuit. The transmission/reception state is monitored and when an antenna which can receive is paired with one which can not, that is to say when the device is faulty or some other kind of emergency has occurred, an antenna which can receive transmits emergency data to an emergency communication receiving center.
Since conventional emergency communication devices are constructed as above, the situation arises that since self diagnosis is carried out by repeatedly transceiving with an emergency communication receiving center using a circuit, the emergency communication receiving center uses many circuits for self diagnosis and so during a real emergency there maybe no available circuit. Moreover the problem has arisen that such self diagnosis using circuits requires considerable communication costs which raises use costs.
The present invention is proposed to solve the above problems by the provision of an emergency communication device which performs self diagnosis without the use of circuits and which immediately communicates with an emergency communication receiving center on the detection of a fault. Furthermore if the antenna is broken or when the vehicle stolen, the emergency communication receiving center is automatically advised of the theft and data is transmitted from the vehicle during the theft.
The self diagnosing emergency communication device of the present invention is provided with a plurality of antennas provided in a vehicle and a communication means which executes self diagnosis by repeatedly transceiving a weak signal which can only be received through an antenna from among said plurality of antennas. When the weak signal is not received, communication regarding the occurrence of an emergency is transmitted to an emergency communication receiving center by a strong signal.
Due to this structure, it is possible to perform self diagnosis without the use of circuits. No costs are involved in self diagnosis and so a low price is possible. Furthermore it is possible to leave circuits open in the emergency communication receiving center for a real emergency communication.
Of course, on the vehicle side during a fault, when an antenna is broken and the weak signal can not be received, the occurrence of an accident is transmitted to the emergency communication receiving center by another functioning antenna. As a result, since it is possible to immediately correct a fault, it is possible to accurately advise of an emergency situation. Furthermore when the vehicle is stolen, appropriate measures are immediately performed by the emergency communication receiving center and at the same time on the basis of the transmission, it is possible to notify persons in the vicinity of the vehicle of the theft. Thus it is possible to prevent the theft from occurring.
Furthermore by performing the transceiving of a weak signal at fixed intervals, it is possible to reduce the deterioration of a battery which acts as a power source.
Furthermore the communication means of the self diagnosing emergency communication device of the present invention is combined with an alarm or a display device or both.
As a result of this structure, it is possible to accurately and easily notify persons in the vicinity of a theft broadcast.
The self diagnosing emergency communication device of the present invention is provided with a GPS receiver which detects a position of the vehicle, a plurality of antennas which are provided in the vehicle, and a communication means which executes self diagnosis by performing the transceiving of a weak signal which can only be received by an antenna from among said plurality of antennas and which when said weak signal is not received, transmits an emergency signal and a vehicle position data by a strong signal to the emergency communication receiving center based on the signal received by said GPS receiver.
As a result of this structure, it is possible to perform self diagnosis without the use of circuits. No costs are involved in self diagnosis and so a low price is possible. Furthermore it is possible to leave circuits open in the emergency communication receiving center for a real emergency communication.
When the weak signal can not be transceived due to damage to or breakage of the antenna, since the emergency communication receiving center is notified of the emergency by another functioning antenna, it is possible to accurately advise of an emergency situation. Furthermore when the vehicle is stolen, appropriate measures are immediately performed by the emergency communication receiving center and at the same time on the basis of the transmission, it is possible to notify persons in the vicinity of the vehicle of the theft. Thus the theft may be prevented. Furthermore since it is possible to notify the emergency communication receiving center of the position of the accident or the position of the stolen vehicle based on the received signal from the GPS receiver, it is possible to quickly perform measures appropriate to the emergency situation.
The self diagnosing emergency communication device of the present invention is provided with transceivers which are respectively connected to a plurality of antennas and a control section which controls the transmitting and receiving of each transceiver.
Due to this arrangement, it is possible to perform self diagnosis smoothly using the respective transceivers as receivers and transmitters without the necessity of a switching means.
The self diagnosing emergency communication device of the present invention is provided with a transceiver transfer means which alternately connects the transmitters and receivers to the plurality of antennas and a control means which controls the transceiving of the transmitters and receivers.
Due to this arrangement, it is possible to simplify the structure for self diagnosis since it is possible to perform self diagnosis only using one transmitter and one receiver with respect to the plurality of antennas.
The control section of the self diagnosing emergency communication device of the present invention is provided with a GPS data storage means which stores calculated vehicle position data based on the signal received by the GPS receiver, a test signal generation means, a emergency data storage means and a CPU which regulates signal level so as to reduce the field level of a transmitted signal during a transmission signal test and to raise the field level of a transmitted signal during the transmission of an emergency signal.
By the above arrangement, the controller can easily transmit emergency data and transceive signals for self diagnosis.
The control section of the self diagnosing emergency communication device of the present invention is provided with a correspondence means which matches based on the instruction data from the emergency communication receiving center received by a receiver.
Due to this arrangement, when becoming lost while driving, it is possible to receive instructions regarding the route by voice messages from the emergency communication center for example by using a radio speaker in the vehicle.